Current location - Training Enrollment Network - Mathematics courses - Several math problems of five stars.
Several math problems of five stars.
(1) Greening workers plant trees 1000m long on both sides of the road at equal intervals (planted at both ends). At first, they planted a tree every 10 meter, and later they planted a tree every 8 meters. How many trees don't use this?

It was originally planned to plant one tree every 10 meter, so it is needed.

1000/10 =100 (two species),100+1=10/.

If you plant one tree every 8 meters, you have to

1000/8= 125

(plant both ends), and you get 125+ 1= 126.

Trees without this species are:1216-101= 25.

Li Jun went to a stationery store to buy stationery. If he bought all the notebooks, he could just buy 10, and if he bought all the pencils, he could just buy 15. Now he has bought four notebooks first. How many pencils can he buy with the remaining money?

Let's assume that 1 notebook costs A yuan and 1 pencil costs B yuan.

De: 10a= 15b

a= 1.5b

10a-4a=6a

6a=

9b

The remaining money can buy nine pencils.